I have a MTR image (Thanks to Benjamin Bender, my hero!). I'd like to use the matlab code below to integrate the values of my image.

I get an error message when I run it

??? Undefined function or method 'spm_get' for input arguments of type 'double'.

I'm on XP using SPM8. I don't know Matlab at all so I'm having problems troubleshooting it. Also, I've masked my image with the grey and white matter segmentations of my highres, this would make a difference in calculation?

thanks, sophie

From John Ashburner 2002  https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind02&L=SPM&P=R33843

If you want to integrate all the values in an image, you would need to write

some kind of a script to do it.  A possible example that you could copy and
paste into Matlab would be:
%____________________________________________________________

V = spm_vol(spm_get(1,'*.img'));
sm = 0;
for i=1:V.dim(3),
        M = spm_matrix([0 0 i]);
        img = spm_slice_vol(V,M,V.dim(1:2),0);
        sm = sm + sum(img(:));
end;
sm
fprintf('%g litres\n', sm*det(V.mat(1:3,1:3))/100^3)
%____________________________________________________________

The value of sm is the integral of intensity throughout the image.  If this
is an integral over a grey matter image, then you will need to scale by the
volume of each voxel ( det(V.mat(1:3,1:3)) )in order to get an answer in
units of cubic millimetres.

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